Positioning devices are known for locating a gasket between two separate but communicating or mating components of an internal combustion engine. The communicating components contain mating bores for the passage of mechanical fasteners. The gasket is adapted to provide sealing between the engine components when they are joined. The positioning devices, also known as grommets, bushings, eyelets, and ferrules, are utilized to help in the accurate placement of the gasket on one of the components to be joined, typically through an interference fit between the device and a bore of the component receiving the device. Positioning devices have included plastic members having tapered bodies for positive placement.
Most positioning devices are separate from the gasket, requiring that they be inserted in an aperture of the gasket after the gasket has been laid over the surface of one of the communicating components. Typically, such positioning devices are not positively retained within the gasket aperture, allowing undesirable separation of the device from the gasket before final assembly. It is known to mold a positioning device in the gasket. However, the positioning device molded in the gasket has less gasket material available to seal between the mating engine components, leading to increased gasket leakage. There are also increased assembly costs associated with molding a positioning device in a gasket.
Plastic positioning devices are known which receive fasteners used to join the mating mechanical components. However, the fasteners are not retained within such positioning devices to prevent unwanted separation of the fasteners from the gasket before final assembly. Instead, separate fastener retention devices are used to retain the fasteners. Typically, a fastener retention device comprises a sleeve with mating threads that threadingly engage a threaded fastener, or protrusions that extend radially inwardly from an inner wall of the sleeve to engage the fastener.